Humidity adjusting device and humidity adjusting method

ABSTRACT

A humidity adjustment device ( 10 ) according to the present disclosure includes a control unit ( 11 ) that acquires humidity information indicating humidity of a space part of a manhole and controls the humidity on the basis of the humidity information.

TECHNICAL FIELD

The present disclosure relates to a humidity adjustment device and ahumidity adjustment method.

BACKGROUND ART

Reinforced concrete having high strength is often used in structuressuch as buildings. In recent years, the deterioration phenomenon ofreinforced concrete has become a social problem. One of thedeterioration phenomena is a neutralization. The Neutralization is thephenomenon in which concrete, which was alkaline during placing,gradually becomes neutral by carbon dioxide in the atmosphere. Theneutralization phenomenon progresses from the surface of concrete incontact with the air. The reinforcement in the reinforced concrete formsa passive state in an alkaline environment, so that corrosion does notprogress, but corrosion progresses in the neutral environment. Thestrength of the reinforced concrete is reduced by the corrosion andthickness reduction of the inside reinforcing bars by theneutralization. As a method for suppressing the neutralization, forexample, PTL 1 discloses a method for making a material resistant to theneutralization by devising the blending of concrete. In PTL 2, a methodfor preventing the carbon dioxide from entering by processing thesurface of concrete is disclosed.

CITATION LIST Patent Literature

-   [PTL 1] Japanese Patent Application Publication No. 2019-147736-   [PTL 2] Japanese Patent Application Publication No. 2011-256065

SUMMARY OF INVENTION Technical Problem

However, a method for controlling the blending of concrete tends toincrease the cost, and cannot be used for already placed reinforcedconcrete. The surface processing method may be undesirable from theviewpoint of the concern of the influence on the human body and theview. In addition, the surface processing is peeled off by weathering orthe like, and the effect may be lost. In this way, it may not beeffective to change the blending of concrete or to apply surfaceprocessing. Therefore, a method for suppressing the neutralization ofconcrete by changing an environment in which concrete exists withoutusing the method for changing the blending p of concrete or the methodfor applying surface processing has been desired. Among them, since thehumidity in the environment is a factor of largely contributing to theneutralization progress speed of concrete and the control of thehumidity is particularly effective for the reinforced concrete existingin a closed space, a humidity adjustment device capable of controllingthe humidity in the environment where a manhole made of the reinforcedconcrete exists has been desired.

An object of the present disclosure made in view of such circumstancesis to provide a humidity adjustment device and a humidity adjustmentmethod capable of controlling the humidity in the manhole made of thereinforced concrete.

Solution to Problem

In order to solve the above problem, a humidity adjustment deviceaccording to the present disclosure includes a control unit thatacquires humidity information indicating humidity of a space part of amanhole and controls the humidity on the basis of the humidityinformation.

The humidity adjustment method according to the present disclosureincludes a step of acquiring the humidity information indicating thehumidity of the space part of the manhole, and a step of controlling thehumidity on the basis of the humidity information.

Advantageous Effects of Invention

According to the present disclosure, the humidity in the reinforcedconcrete manhole can be controlled.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing an outline of a system including a humidityadjustment device according to a first embodiment of the presentdisclosure.

FIG. 2 is a diagram showing a configuration example of a manhole.

FIG. 3 is a block diagram showing a configuration of the systemincluding the humidity adjustment device according to the firstembodiment of the present disclosure.

FIG. 4 is a diagram showing an operation example of the system includingthe humidity adjustment device according to the first embodiment of thepresent disclosure.

FIG. 5 is a flowchart showing the operation of a control unit of thehumidity adjustment device according to the first embodiment of thepresent disclosure.

FIG. 6 is a diagram showing an outline of a system including a humidityadjustment device according to a second embodiment of the presentdisclosure.

FIG. 7 is a block diagram showing a configuration of a system includingthe humidity adjustment device according to the second embodiment of thepresent disclosure.

FIG. 8 is a diagram showing an application example of the humidityadjustment device according to the second embodiment of the presentdisclosure.

FIG. 9 is a diagram showing an operation example of the system includingthe humidity adjustment device according to the second embodiment of thepresent disclosure.

FIG. 10 is a flowchart showing the operations of a control unit of thehumidity adjustment device according to the second embodiment of thepresent disclosure.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a embodiment of the present disclosure will be describedwith reference to the drawings. The embodiments to be described beloware configuration examples of the present disclosure and are notintended to limit the present disclosure.

First Embodiment

An outline of a system 1 according to a first embodiment of the presentdisclosure will be described with reference to FIG. 1 . As shown in FIG.1 , the system 1 includes, in a manhole M, a humidity adjustment device10, a humidifier 20, a space part thermo-hygrometer 30 and an inner wallsurface thermometer 40. The humidity adjustment device 10 includes acontrol unit 11, a storage unit 12, a communication unit 13, an inputunit 14, and an output unit 15. The humidity adjustment device 10, thehumidifier 20, the space part thermo-hygrometer 30, and the inner wallsurface thermometer 40 are connected to be communicable by wire orwireless. There is no particular limitation on the communication methodfor transmitting/receiving of information between the humidityadjustment device 10, the humidifier 20, the space partthermo-hygrometer 30, and the inner wall surface thermometer 40. Thehumidity adjustment device 10 may be installed outside the manhole M.

The configuration of the manhole M will be briefly described here withreference to FIG. 2 . The manhole M is an underground structure made ofthe reinforced concrete. The manhole M includes a neck part 210, a framepart 220, and an iron cover 230. The frame part 220 includes a ceilingpart 221, a floor part 222, and a side wall part 223. The neck part 210is connected to the ceiling part 221 of the frame part 220. A space partS exists in the frame part 220, and the space part S is surrounded by aninner wall surface I. The inner wall surface I includes a ceilingsurface R of the ceiling part 221, a side wall surface H of the sidewall part 223, and a floor surface F of the floor part 222. One end ofthe neck part 210 is connected to the ceiling surface R of the framepart 220, and the other end of the neck part 210 is exposed to theground. The frame part 220 and the neck part 210 are made from thereinforced concrete.

Referring back to FIG. 1 , the humidifier 20, the space partthermo-hygrometer 30 and the inner wall surface thermometer 40 will bedescribed.

The humidifier 20 discharges moisture in the space part S of the manholeM and humidifies the space part S. As disclosed in the followingLiterature 1, it has been found that the humidity in the environment isa factor that greatly contributes to the rate of progress of theneutralization of concrete. Therefore, in this embodiment, the humidityof the space part S is controlled by the humidifier 20. Literature 1:Toshio Shirakawa, and two others, “A study on Carbonation of Concrete byInfluence of Humidity”, Proceeding of the Japan Concrete Institute, Vol.18, No. 1, 1996

In this embodiment, the humidifier 20 is a steam type humidifier. Thehumidifier 20 is not limited to this, but may be an ultrasonic typehumidifier or a vaporization type humidifier. The humidifier 20 includesa heater, an evaporation pan, a fan, an openable/closable jetting port,a water supply tank and a control unit. The control unit of thehumidifier 20 controls the heater, the fan and the jetting port. In thehumidifier 20, water is supplied from the water supply tank to theevaporation pan, and a heater provided on a bottom surface of theevaporation pan heats the water. The heated and evaporated water isdischarged to the outside from the jetting port by the fan to humidifythe space part S. The discharge amount of moisture from the humidifier20 is adjusted by opening and closing the jetting port. The water supplytank supplies water to the evaporation pan from above the evaporationpan. A water supply valve is provided at the bottom of the water supplytank, and when the water supply tank is installed, a push-in pinprovided on the evaporation pan pushes up the water supply valve frombelow. Thus, the water supply valve is opened, and water is supplied tothe evaporation pan. The control unit of the humidifier 20 controls theoperation of the whole humidifier 20 according to an instructionreceived from the control unit 11 of the humidity adjustment device 10.

The space part thermo-hygrometer 30 is an equipment for measuring thetemperature and humidity of the space part S of the manhole M. The spacepart thermo-hygrometer 30 includes a temperature and humidity sensor, acontrol unit, a storage unit, and a communication unit. The temperatureand humidity sensor detects the temperature and humidity of the spacepart S, and stores the detected temperature and humidity in the storageunit as space part temperature information and humidity information,respectively. The control unit transmits the space part temperatureinformation and the humidity information to the humidity adjustmentdevice 10 via the communication unit. The space part temperatureinformation and the humidity information may be transmitted at all timesor may be transmitted in response to an instruction from the humidityadjustment device 10. In the present embodiment, the space partthermo-hygrometer 30 is mounted on the side wall surface H of themanhole M, but the position of the space part thermo-hygrometer 30 isnot limited thereto. For example, the space part thermo-hygrometer 30may be mounted on a support leg extending from the floor part 222 towardthe ceiling part 221 to measure the temperature and humidity of thespace part S at a position of a predetermined height from the floorsurface F. The control unit of the space part thermo-hygrometer 30controls the operation of the whole space part thermo-hygrometer 30according to the instruction received from the humidity adjustmentdevice 10.

The inner wall surface thermometer 40 is an equipment for measuring thetemperature of the inner wall surface I of the manhole M. The inner wallsurface thermometer 40 includes a temperature sensor, a storage unit,and a communication unit. The temperature sensor of the inner wallsurface thermometer 40 detects the temperature of the inner wall surfaceI, and stores the detected temperature in the storage unit as the innerwall surface temperature information. The control unit transmits theinner wall surface temperature information to the humidity adjustmentdevice 10 via the communication unit. The transmission of the inner wallsurface temperature information may be always performed or may beperformed in response to an instruction from the humidity adjustmentdevice 10. In this embodiment, the inner wall surface thermometer 40 ismounted on the ceiling surface R of the manhole M. The temperaturesensor detects the temperature of the ceiling surface R, and stores thedetected temperature in the storage unit as the inner wall surfacetemperature information. The control unit of the inner wall surfacethermometer 40 controls the operation of the whole inner wall surfacethermometer 40 according to the instruction received from the humidityadjustment device 10.

FIG. 3 is the block diagram showing a configuration of the system 1including the humidity adjustment device 10 according to the presentembodiment. The control unit 11 of the humidity adjustment device 10includes a critical humidity value calculation unit 111 and an operationdetermination unit 112. The control unit 11 acquires the humidityinformation indicating the humidity of the space part S of the manhole Mand the space part temperature information indicating the temperature ofthe space part S from the space part thermo-hygrometer 30 via thecommunication unit 13. The control unit 11 further acquires the innerwall surface temperature information indicating the temperature of theinner wall surface I of the manhole M from the inner wall surfacethermometer 40 via the communication unit 13. Specifically, the innerwall surface temperature information indicates the temperature of theceiling surface R. The control unit 11 stores the acquired humidityinformation, space part temperature information and inner wall surfacetemperature information in the storage unit 12. The critical humidityvalue calculation unit 111 calculates a critical humidity value at whichdew condensation does not occur in the manhole M on the basis of thespace part temperature information, the inner wall surface temperatureinformation, and the humidity information. The operation determinationunit 112 determines the operation of the humidifier 20 so that thehumidity is maintained in a range equal to or higher than a referencehumidity value and lower than the critical humidity value. The controlunit 11 transmits an instruction of the determined operation to thehumidifier 20. The humidifier 20 receives the instruction and performsoperation based on the instruction.

The “reference humidity value” is a humidity value for suppressingprogress of the neutralization of concrete constituting the manhole M.As disclosed in the following Literature 2, it has become clear that theneutralization of concrete does not proceed substantially when therelative humidity is 90 percent or more. Therefore, in the presentembodiment, the humidity is controlled so that the humidity of the spacepart S of the manhole M is equal to or higher than the referencehumidity value. In this embodiment, the reference humidity value is setto 90 percent. The reference humidity value is not limited to thisvalue, but may be freely set.

Literature 2: Hisatoshi Kasahara, and two others, “Progress behavior ofneutralization in a reinforced concrete manhole for communication”, the74th Annual Conference of the Japan Society of Civil Engineers, V-352,2019

The “critical humidity value” is a value of the critical humidity atwhich dew condensation occurs on the inner wall surface I of the manholeM. In this embodiment, the value of the critical humidity at which dewcondensation occurs on the ceiling surface R of the manhole M isspecifically shown. As disclosed in the following Literature 3, when theinside of the manhole M is continuously humidified, the moisture in theair exceeds the saturated water vapor pressure and becomes a liquid.Since a large amount of liquid water in the manhole M interfere with thework in the manhole, and corrodes the reinforcing bars exposed from thereinforced concrete of the manhole M as dew condensation, it ispreferable that the liquid water is not generated as much as possible.

Literature 3: Hisatoshi Kasahara, and two others, “influence oftemperature on corrosion behavior of reinforcing bars due to dewcondensation”, the 73th Annual Conference of the Japan Society of CivilEngineers, VI-235, 2018

Further, in the following Literature 4, it is disclosed that dewcondensation occurs in many manholes M even if humidity is 100 percentor less due to the temperature of the ceiling part 221 becoming lowerthan that of the inside air. Therefore, in the present embodiment, thehumidity is controlled so that the humidity of the space part S of themanhole M is less than the critical humidity value.

Literature 4: Norihiro Fujimoto, and two others, “Dew condensationoccurrence mechanism in manhole for communication”, the 73th AnnualConference of the Japan Society of Civil Engineers, V-395, 2018

The control unit 11 of the humidity adjustment device 10 includes one ormore processors. In the present embodiment, “processor” may be ageneral-purpose processor, or a dedicated processor specialized inspecific processing, but not limited to these. The control unit 11 maybe configured by dedicated hardware, or may be configured by ageneral-purpose processor or a processor specialized for specificprocessing. The control unit 11 executes processing related to theoperation of the whole humidity adjustment device 10 while controllingeach part of the humidity adjustment device 10. Also, the control unit11 includes a critical humidity value calculation unit 111 and aoperation determination unit 112. One or more programs used forcontrolling the operation of the control unit 11 are stored in thestorage unit 12, and the programs are read by the control unit 11, sothat the control unit 11 functions as the critical humidity valuecalculation unit 111 and the operation determination unit 112.

The control unit 11 controls the humidity of the space part S of themanhole M, as will be described in detail below. The control isperformed by transmitting the instruction of the operation determined bythe operation determination unit 112 to the humidifier 20 via thecommunication unit 13.

First, the control unit 11 acquires, from the space partthermo-hygrometer 30 and the inner wall surface thermometer 40, measuredspace part temperature information, humidity information, and inner wallsurface temperature information by receiving them via the communicationunit 13. The control unit 11 may acquire the space part temperatureinformation, the humidity information, and the inner wall surfacetemperature information periodically or non-periodically.

Next, the operation determination unit 112 compares the humidityincluded in the humidity information with a reference humidity value,and determines whether the humidity is less than the reference humidityvalue.

The operation determination unit 112 determines the operation of thehumidifier 20 so that the humidifier 20 performs a large amount ofhumidification when it is determined that the humidity is less than thereference humidity value. The operation determination unit 112 transmitsan instruction of operation to the humidifier 20 via the communicationunit 13. The “large amount of humidification” means to increase theamount of moisture discharged from the humidifier 20, to prolong theduration of the humidifying operation, or the like, and may be freelydetermined by the function of the humidifier 20.

The critical humidity value calculation unit 111 calculates the criticalhumidity value by referring to the space part temperature informationand the inner wall surface temperature information. The criticalhumidity value calculation unit 111 first calculates a value of e basedon the following Equation

[Math.1] $\begin{matrix}{e = {6.1078 \times 10^{\frac{7.5T}{T + 237.3}}}} & {{Equation}(1)}\end{matrix}$

In the Equation (1), T represents the temperature of the space part S ofthe manhole M included in the space part temperature information, andthe unit is the Celsius temperature (□). The calculated value e is thevalue of the saturated water vapor steam pressure when the temperatureof the space part S of the manhole M is T, and the unit is hPa. In thisexample, the value e is calculated by using the Equation (1), but otherapproximate equations may be used in addition to the Equation (1).

Next, the critical humidity value calculation unit 111 calculates thevalue of a on the basis of the following Equation (2).

[Math.2] $\begin{matrix}{a = \frac{217 \times e}{T + 273.15}} & {{Equation}(2)}\end{matrix}$

The value a calculated by the Equation (2) is a value of a saturatedwater vapor amount when the temperature of the space part S of themanhole M is T, and a unit is m³/g.

Next, the critical humidity value calculation unit 111 calculates avalue of e′ based on the following Equation (3).

[Math.3] $\begin{matrix}{e^{\prime} = {6.1078 \times 10^{\frac{7.5t}{t + 237.3}}}} & {{Equation}(3)}\end{matrix}$

In the Equation (3), t represents the temperature of the ceiling surfaceR of the manhole M included in the inner wall surface temperatureinformation, and the unit is the Celsius temperature (□). The calculatedvalue e′ is a value of the saturated water vapor pressure when the airin the manhole M hits the ceiling surface R and the temperature of thespace part S reaches t, and the unit is hPa. In this example, the valuee′ is calculated by using the Equation (3), but other approximateequations may be used in addition to the Equation (3).

Next, the critical humidity value calculation unit 111 calculates avalue of a′ based on the following Equation (4).

[Math.4] $\begin{matrix}{a^{\prime} = \frac{217 \times e^{\prime}}{t + 273.15}} & {{Equation}(4)}\end{matrix}$

The value a′ calculated by the Equation (4) is a value of a saturatedwater vapor amount when the air in the manhole M hits the ceilingsurface R and the temperature of the space part S reaches t, and theunit is m³/g.

Next, the critical humidity value calculation unit 111 calculates thecritical humidity value based on the following Equation (5).

[Math.5] $\begin{matrix}{{a^{\prime} \times \frac{100}{100}} = {a \times \frac{X}{100}}} & {{Equation}(5)}\end{matrix}$

The Equation (5) indicates that the value a′ which is the value of thesaturated water vapor amount (that is, the value of the water vaporamount at which the air coming into contact with the ceiling surface Rof the manhole M and having a temperature T starts dew condensation) isequal to the water vapor amount at the humidity of X percent under anenvironment where the space part S of the manhole M is the temperatureT. The value X is calculated as the critical humidity value.

The critical humidity value calculation unit 111 outputs informationindicating the critical humidity value thus calculated to the operationdetermination unit 112.

The operation determination unit 112 determines whether or not thehumidity included in the humidity information is less than the criticalhumidity value. When it is determined that the humidity is equal to orhigher than the reference humidity value and less than the criticalhumidity value, the operation determination unit 112 determines theoperation of the humidifier 20 so that the humidifier 20 performs asmall amount of humidification. The operation determination unit 112transmits an instruction of an operation so as to perform the smallamount of humidification to the humidifier 20 via the communication unit13. The “small amount of humidification” means that humidification isperformed in a state where the amount of moisture discharged from thehumidifier 20 is reduced, or the duration of the humidificationoperation is shortened, and may be determined by the function of thehumidifier 20.

When the operation determination unit 112 determines that the humidityis equal to or higher than the reference humidity value and equal to orhigher than the critical humidity value, the operation determinationunit 112 determines that the humidifier 20 stops humidification, Theoperation of the humidifier 20 is determined. The operationdetermination unit 112 transmits an instruction of an operation to thehumidifier 20 so as to stop humidification through the communicationunit 13.

The storage unit 12 includes one or more memories and may include, forexample, a semiconductor memory, magnetic memory, optical memory, and soon. Each of the memories included in the storage unit 12 may function,for example, as a main memory device, an auxiliary memory device, or acache memory. The storage unit 12 stores various types of informationused for the operation of the humidity adjustment device 10. The storageunit 12 stores the humidity information, the space part temperatureinformation, and the inner wall surface temperature information acquiredby the control unit 11. The storage unit 12 also stores informationindicating the reference humidity value.

The communication unit 13 includes at least one communication interface.The communication interface is, for example, a LAN interface. Thecommunication unit 13 receives information used for the operation of thehumidity adjustment device 10, and transmits information obtained by theoperation of the humidity adjustment device 10.

The input unit 14 includes at least one input interface. The inputinterface includes, for example, a physical key, a capacitive key, apointing device, a touch screen provided integrally with a display, anda microphone. The input unit 14 receives an operation for inputtinginformation used for the operation of the humidity adjustment device 10.The input unit 14 can directly receive a input such as informationindicating the humidity information, the space part temperatureinformation, the inner wall surface temperature information, thereference humidity value or information indicating the critical humidityvalue from a user.

The output unit 15 includes at least one output interface. The outputinterface is, for example, a display or a speaker. The display may be aliquid crystal display, an organic EL display, an inorganic EL display,or the like. The output unit 15 may be a touch panel, and in this case,the output unit 15 displays various types of information to the user andfunctions as the input unit 14 for receiving the input by the operationof the user.

<Program>

The humidity adjustment device 10 may be a computer capable of executingprogram instructions. The computer stores a program in which theprocessing content for realizing each function of the humidityadjustment device 10 in the storage unit of the computer, and loads andexecutes this program using a processor of the computer. A part of theseprocessing contents may be realized by the hardware. Here, the computermay be any of a general purpose computer, dedicated computer, workstation, PC (Personal Computer), electronic notepad, and so on. Theprogram commands may be program codes, code segments, or the like forexecuting necessary tasks. The processor may be CPU (Central ProcessingUnit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor),and so on.

This program may be recorded on a computer-readable recording medium.With the use of such a recording medium, the program can be installedinto the computer. The recording medium in which the program is recordedmay also be a non-transitory recording medium. The non-transitoryrecording medium may be, but is not particularly limited to, a recordingmedium such as a CD-ROM or a DVD-ROM. This program can also be madeavailable by downloading it via a network.

Next, the operation of the system 1 including the humidity adjustmentdevice 10 according to the present embodiment will be described withreference to FIGS. 4 and 5 . Among the operations of the system 1, theoperation of the humidity adjustment device 10 corresponds to thehumidity adjustment method according to the present embodiment. FIG. 4shows an example of the operation of the system 1. FIG. 5 is theflowchart showing the operation example of the control unit 11 of thehumidity adjustment device 10. In this example, it is assumed that thehumidifier 20 is under operation.

In a step S101, the control unit of the space part thermo-hygrometer 30refers to the storage unit and transmits the space part temperatureinformation and the humidity information to the humidity adjustmentdevice 10 via the communication unit.

In a step S102, the control unit of the inner wall surface thermometer40 refers to the storage unit and transmits the inner wall surfacetemperature information to the humidity adjustment device 10 via thecommunication unit.

In a step S103, the control unit 11 of the humidity adjustment device 10receives, via the communication unit 13, the apace part temperatureinformation, the humidity information, the inner wall surfacetemperature information from the space part thermo-hygrometer 30 and theinner wall surface thermometer 40 to acquire these information. Thecontrol unit 11 stores the acquired space part temperature information,humidity information, and inner wall surface temperature information inthe storage unit 12.

In a step S104, the control unit 11 determines an operation to beinstructed to the humidifier 20. FIG. 5 shows a specific processing flowof the determination of the operation in step S104.

In a step S201, the operation determination unit 112 reads the humidityinformation and the reference humidity value stored in the storage unit12. The operation determination unit 112 compares the humidity includedin the humidity information with the reference humidity value, anddetermines whether the humidity is less than the reference humidityvalue.

When the humidity is less than the reference humidity value, theoperation determination unit 112 determines the operation of thehumidifier 20 so that the humidifier 20 performs the large amount ofhumidification in a step S202, and the process for determining theoperation is terminated. When the humidity is equal to or higher thanthe reference humidity value, processing for determining the operationproceeds to a step S203. In this example, the humidity is 95 percent andthe reference humidity value is 90 percent. Since the humidity is equalto or higher than the reference humidity value, the processing fordetermining the operation proceeds to the step S203.

In the step S203, the critical humidity value calculation unit 111refers to the space part temperature information, the inner wall surfacetemperature information, and the humidity information, and calculatesthe critical humidity value. The critical humidity value calculationunit 111 outputs the information indicating the calculated criticalhumidity value to the operation determination unit 112.

Next, in a step S204, the operation determination unit 112 compares thehumidity with the critical humidity value and determines whether thehumidity is less than the critical humidity value.

When the humidity is less than the critical humidity value, theoperation determination unit 112 determines the operation of thehumidifier 20 so that the humidifier 20 performs the small amount ofhumidification in a step S205, and the process for determining theoperation is terminated. When the humidity is equal to or higher thanthe critical humidity value, the operation determination unit 112determines the operation of the humidifier 20 so that the humidifier 20stops humidification in a step S206. In this example, the humidity is 95percent and the critical humidity value is 94 percent. Since thehumidity is equal to or higher than the critical humidity value, theoperation determination unit 112 determines the operation for stoppinghumidification in the step S206. Thus, the process of determining theoperation to instruct the humidifier 20 is completed.

Then, returning to FIG. 4 , in a step S105, the operation determinationunit 112 transmits an instruction of the operation to the humidifier 20via the communication unit 13 so as to execute the processing of thedetermined operation. The humidifier 20 is continued in this way. Inthis example, since the determined operation is the operation forstopping humidification, the control unit 11 transmits the instructionof the operation for stopping humidification to the humidifier 20 viathe communication unit 13.

In a step S106, the control unit of the humidifier 20 receives theinstruction of the operation from the humidity adjustment device 10 viathe communication unit. In this example, the control unit of thehumidifier 20 receives the instruction of the operation to stophumidification.

In a step S107, the humidifier 20 operates according to the instructionfrom the humidity adjustment device 10.

Specifically, the control unit of the humidifier 20 controls each unitof the humidifier 20 so as to operate according to the receivedinstruction. In this embodiment, the heater, the fan, and the jettingport of the humidifier 20 are controlled so as to stop thehumidification.

The humidity of the space part S of the manhole M is controlled by thesteps S101 to S107.

As described above, the humidity adjustment device 10 according to thepresent embodiment includes the control unit 11 for acquiring thehumidity information indicating the humidity of the space part S of themanhole M and controlling the humidity based on the humidityinformation.

According to this embodiment, the humidity in the manhole M made of thereinforced concrete can be controlled. The humidity of the space part Sof the manhole M is controlled to be an appropriate value, so that theprogress of neutralization of concrete constituting the manhole M can beprevented.

As described above, in the humidity adjustment device 10 according tothe present embodiment, the control unit 11 further acquires the spacepart temperature information indicating the temperature of the spacepart S of the manhole M and the inner wall surface temperatureinformation indicating the temperature of the inner wall surface I ofthe manhole M, calculates the critical humidity value at which dewcondensation does not occur in the manhole M on the basis of the spacepart temperature information, the inner wall surface temperatureinformation, and the humidity information, and controls the humidity onthe basis of a result of comparing the critical humidity value with thehumidity.

According to the present embodiment, the critical humidity value iscalculated based on the temperature and humidity of the space part S ofthe manhole M and the temperature of the ceiling surface R included inthe inner wall surface I. Since the humidity can be controlled bycomparing the critical humidity value with the humidity, the occurrenceof dew condensation due to excessive humidification in the manhole M canbe prevented.

As described above, the humidity adjustment device 10 according to thepresent embodiment further includes the communication unit 13 forcommunicating with the humidifier 20 for humidifying the inside of themanhole M. The control unit 11 of the humidity adjustment device 10determines the operation of the humidifier 20 so that the humidity ismaintained in a range of the reference humidity value or more and lessthan the critical humidity value, and transmits the determined operationto the humidifier 20 via the communication unit 13.

According to the present embodiment, the humidity in the manhole M canbe controlled more accurately by controlling the operation of thehumidifier 20. By the operation of the humidifier 20, the humidity inthe manhole M can be maintained at the humidity where the progress ofneutralization of concrete is suppressed and dew condensation does notoccur.

Second Embodiment

Below, the difference between the first embodiment and the presentembodiment will be described.

FIG. 6 shows the outline of a system 2 according to the presentembodiment. Referring to FIG. 6 , the present embodiment is differentfrom the first embodiment in that a water supply device 50 is providedin place of the humidifier 20. The humidity adjustment device 10, thewater supply device 50, the space part thermo-hygrometer 30, and theinner wall surface thermometer 40 are connected to be communicable bywire or wireless. The communication method for transmitting andreceiving information between the humidity adjustment device 10, thewater supply device 50, the space part thermo-hygrometer 30, and theinner wall surface thermometer 40 is not particularly limited. Thehumidity adjustment device 10 may be installed outside the manhole M.

The water supply device 50 is a device for storing water in a liquidstate so as to evaporate moisture in the space part S of the manhole M.The water supply device 50 includes a water supply container 51, anopenable/closable cover 52, a water supply tank 53, a water supplypassage 54, a water level sensor 55, a water supply pump, a motor, thecontrol unit, the storage unit, and the communication unit. The controlunit of the water supply device 50 controls the cover 52, the watersupply pump, and the motor. In this embodiment, the water supply tank 53is provided on the ground as shown in FIG. 6 , but may be provided inthe manhole M. In the water supply device 50, water is sucked up fromthe water supply tank 53 by the water supply pump and sent into thewater supply passage 54. The water is discharged from the terminal endof the water supply passage 54 to the water supply container 51. Themanhole M is humidified by evaporation of water from the water supplycontainer 51. The water supply pump is driven by the motor, and themotor is controlled by the control unit of the water supply device 50.The water level sensor 55 detects the water level in the water supplycontainer 51. The control unit of the water supply device 50 acquiresthe water level detected by the water level sensor 55, calculates thewater amount in the water supply container 51, and stores it in thestorage unit as water amount information. The water amount can becalculated on the basis of the volume of the water supply container 51previously stored in the storage unit. The control unit of the watersupply device 50 transmits the water amount information to the humidityadjustment device 10 via the communication unit. The water amountinformation may be transmitted at all times or may be transmitted inresponse to an instruction from the humidity adjustment device 10. Byopening and closing the cover 52, the evaporation amount of moisturefrom the water supply device 50 is adjusted. The control unit of thewater supply device 50 controls the operation of the whole water supplydevice 50 according to an instruction received from the control unit 11of the humidity adjustment device 10.

FIG. 7 is the block diagram showing a configuration of the system 2according to the present embodiment. In the humidity adjustment device10 shown in FIG. 7 , compared with the humidity adjustment device 10 ofthe first embodiment shown in FIG. 3 , it is different from the firstembodiment that the humidity adjustment device 10 communicates with thewater supply device 50 instead of the humidifier 20, information istransmitted from the water supply device 50 to the humidity adjustmentdevice 10, and the control unit 11 further includes a required wateramount calculation unit 113.

As in the first embodiment, the control unit 11 of the humidityadjustment device 10 acquires the humidity information, the space parttemperature information, and the inner wall surface temperatureinformation. The control unit 11 further acquires the water amountinformation indicating the water amount in the water supply device 50from the water supply device 50. The control unit 11 stores the acquiredhumidity information, space part temperature information, inner wallsurface temperature information and water amount information in thestorage unit 12. The critical humidity value calculation unit 111calculates the critical humidity value in the same manner as in thefirst embodiment. The required water amount calculation unit 113calculates the water amount required for the water supply device 50based on the space part temperature information, the inner wall surfacetemperature information, the humidity information, and the informationindicating the critical humidity value. The operation determination unit112 determines the operation of the water supply device 50 so that thehumidity is maintained in the range equal to or higher than thereference humidity value and less than the critical humidity value.

Specifically, the operation determination unit 112 determines theoperation of the water supply device 50 on the basis of a result ofcomparing the required water amount with the water amount in the watersupply device 50. The control unit 11 transmits an instruction of thedetermined operation to the water supply device 50. The water supplydevice 50 receives the instruction and performs the operation based onthe instruction.

The “required water amount” is the water amount which is insufficient toset the humidity of the space part S of the manhole M to the criticalhumidity value. Specifically, the required water amount is calculated asthe water vapor amount as shown below.

The control unit 11 controls the humidity of the space part S of themanhole M, as will be described in detail below. The control isperformed by transmitting the instruction of the operation determined bythe operation determination unit 112 to the water supply device 50 viathe communication unit 13.

First, as in the first embodiment, the control unit 11 acquires thespace part temperature information, the humidity information, and theinner wall surface temperature information. The control unit 11 furtheracquires the water amount information from the water supply device 50 byreceiving the water amount information via the communication unit 13.The control unit 11 may acquire the space part temperature information,the humidity information, the inner wall surface temperatureinformation, and the water amount information periodically ornon-periodically.

Next, the operation determination unit 112 compares the humidityincluded in the humidity information with the reference humidity value,and determines whether the humidity is less than the reference humidityvalue, as in the first embodiment.

When it is determined that the humidity is less than the referencehumidity value, the operation determination unit 112 determines theoperation of the water supply device 50 so that the water supply device50 takes in water. The operation determination unit 112 transmits theinstruction of operation to the water supply device 50 via thecommunication unit 13. “Taking in water” means that the control unit ofthe water supply device 50 controls the motor or the cover 52 to addwater into the water supply container 51 or prevent evaporation in thepresent embodiment, however it may be freely determined by the functionof the water supply device 50.

The critical humidity value calculation unit 111 calculates the criticalhumidity value by the same method as in the first embodiment. Thecritical humidity value calculation unit 111 outputs the informationindicating the calculated critical humidity value to the required wateramount calculation unit 113.

The required water amount calculation unit 113 refers to the humidityinformation, the space part temperature information, the inner wallsurface temperature information, and the information indicating thecritical humidity value, and calculates the required water amount to besupplied to the water supply device 50. The required water amountcalculation unit 113 calculates the value of A based on the followingEquation (6).

[Math.6] $\begin{matrix}{A = {a \times V \times \frac{RH}{100}}} & {{Equation}(6)}\end{matrix}$

In the Equation (6), a represents the value of the saturated water vaporamount when the temperature of the space part S of the manhole M is T,and the calculation method is the same as that of the method shown inthe first embodiment, so that the description thereof is omitted. In theEquation (6), V is the space volume in the manhole, and the unit is m³.RH is the humidity of the space part S, and the unit is percent. Thevalue A to be calculate is the water vapor amount existing in the spacepart S of the manhole M, and the unit is g.

Next, the required water amount calculation unit 113 calculates thevalue of B based on the following Equation (7).

[Math. 7]

B=a′×V+A  Equation (7)

In the Equation (7), the term a′xV indicates the water vapor amountexisting in the space part S when the humidity in the space part S ofthe manhole M is the critical humidity value. The value B to becalculated is the water vapor amount which is insufficient to set thehumidity of the space part S of the manhole M to the critical humidityvalue, and the unit is g.

The required water amount calculation unit 113 outputs the water vaporamount calculated in this way to the operation determination unit 112 asthe required water amount. Since the water which is the require wateramount evaporates in the space part S, the humidity in the space part Sapproaches the critical humidity value. Thus, the humidity of the spacepart S can be maintained within the range of the reference humidityvalue or more and less than the critical humidity value by calculatingand using the required water amount.

The operation determination unit 112 determines whether or not the wateramount included in the water amount information is equal to or more thanthe required water amount.

The operation determination unit 112 determines the operation of thewater supply device 50 so that the water supply device 50 stops takingin the water into the water supply container 51 when it is determinedthat the humidity is equal to or higher than the reference humidityvalue and the water amount is equal to or higher than the required wateramount. The operation determination unit 112 transmits the instructionof operation to the water supply device 50 via the communication unit13.

The operation determination unit 112 determines the operation of thewater supply device 50 so that the water supply device 50 takes in thewater into the water supply container 51 when it is determined that thehumidity is equal to or higher than the reference humidity value and thewater amount is less than the required water amount. The operationdetermination unit 112 transmits the instruction of operation to thewater supply device 50 via the communication unit 13.

FIG. 8 shows a result of controlling the humidity of the space part S ofthe manhole M using the water supply device 50 according to the presentembodiment. FIG. 8 is a graph showing a change in humidity in the spacepart S of the manhole M. The vertical axis represents the humidity ofthe space part S of the manhole M, and the horizontal axis representsthe date of measuring the humidity. On May 20, 2019, the water in thewater supply container 51 of the water supply device 50 installed in themanhole M is completely removed, and the humidity of the space part S inthe manhole M is set to the humidity equal to the outside air.Thereafter, the water is supplied into the water supply container 51,and the iron cover 230 of the manhole M is closed. According to thegraph of FIG. 8 , it can be seen that the value of humidity in themanhole M changes up and down for about 10 days from May 20, 2019, wherethe water supply device 50 is disposed. This change is considered toshow such behavior as the saturated water vapor amount changes with thechange of the temperature in the manhole M. On the other hand, after May30, 2019, which is the tenth day from May 20, 2019, the humidity of thespace part S of the manhole M is maintained at a high humidity of about100 percent. This is considered to be due to the evaporation action ofwater from the installed water supply device 50. As shown in FIG. 8 , itcan be seen that the humidity of the space part S of the manhole M canbe effectively controlled by using the water supply device 50.

Next, the difference between the operation of the system 1 according tothe first embodiment and the operation of the system 2 according to thepresent embodiment will be described. FIG. 9 shows an example of theoperation sequence of the system 2. FIG. 10 is the flowchart showing anoperation example of the control unit 11 of the humidity adjustmentdevice 10 according to the present embodiment. In this example, it isassumed that the water is supplied to the water supply device 50.

The steps S301 to S302 in FIG. 8 are similar to the steps S101 to S102in FIG. 4 according to the first embodiment and therefore thedescription will not omitted.

In a step S303, the control unit of the water supply device 50 refers tothe storage unit, and transmits the water amount information indicatingthe water amount in the water supply device 50 to the humidityadjustment device 10 via the communication unit.

In a step S304, the control unit 11 of the humidity adjustment device 10receives, via the communication unit 13, the space part temperatureinformation, the humidity information, the inner wall surfacetemperature information from the space part thermo-hygrometer 30, theinner wall surface thermometer 40 and the water supply device 50 andacquires these information. The control unit 11 stores the acquiredspace part temperature information, the humidity information, the innerwall surface temperature information, and the water amount informationin the storage unit 12.

In a step S305, the control unit 11 determines an operation to beinstructed to the water supply device 50. FIG. 10 shows a specificprocessing flow of the determination of the operation in step S305.

In a step S401, the operation determination unit 112 reads the humidityinformation and the reference humidity value stored in the storage unit12. The operation determination unit 112 compares the humidity includedin the humidity information with the reference humidity value, anddetermines whether the humidity is less than the reference humidityvalue.

When the humidity is less than the reference humidity value, theoperation determination unit 112 determines the operation of the watersupply device 50 so that the water supply device 50 takes in the waterin a step S402, and the processing for determining the operation isterminated. When the humidity is equal to or higher than the referencehumidity value, processing for determining the operation proceeds to astep S403. In this example, the humidity is 95 percent and the referencehumidity value is 90 percent. Since the humidity is equal to or higherthan the reference humidity value, the processing for determining theoperation proceeds to the step S403.

In the step S403, the critical humidity value calculation unit 111refers to the space part temperature information, the inner wall surfacetemperature information, and the humidity information, and calculatesthe critical humidity value. The critical humidity value calculationunit 111 outputs the information indicating the calculated criticalhumidity value to the required water amount calculation unit 113.

In a step S404, the required water amount calculation unit 113 refers tothe humidity information, the space part temperature information, theinner wall surface temperature information, and the informationindicating the critical humidity value and calculates the required wateramount to be supplied to the water supply device 50. The required wateramount calculation unit 113 outputs the information indicating thecalculated required water amount to the operation determination unit112.

Next, in a step S405, the operation determination unit 112 compares thewater amount with the required water amount, and determines whether thewater amount is equal to or more than the required water amount.

When the water amount is equal to or more than the required wateramount, the operation determination unit 112 determines the operation ofthe water supply device 50 so as to stop the water supply device 50 fromtaking in the water in a step S406, and the processing for determiningthe operation is terminated. When the water amount is less than therequired water amount, the operation determination unit 112 determinesthe operation of the water supply device 50 so that the water supplydevice 50 takes in the water in the step S402. In this example, thewater amount is less than the required water amount. Therefore, theoperation determination unit 112 determines the operation of the watersupply device 50 so that the water supply device 50 takes in the waterin a step S402. Thus, the process for determining the operation to beinstructed to the water supply device 50 is completed.

Then, returning to FIG. 9 , in a step S306, the operation determinationunit 112 transmits the instruction of the operation to the water supplydevice 50 so as to execute the processing of the determined operationvia the communication unit 13. Thus, the water supply device 50 iscontrolled. In this example, since the determined operation is theoperation for taking in the water, the control unit 11 transmits theinstruction of the operation to the water supply device 50 so as to takein the water via the communication unit 13.

In a step S307, the control unit of the water supply device 50 receivesthe instruction of the operation from the humidity adjustment device 10via the communication unit. In this example, the control unit of thewater supply device 50 receives the instruction for taking in the water.

In a step S308, the water supply device 50 operates according to theinstruction from the humidity adjustment device 10. Specifically, thecontrol unit of the water supply device 50 controls each part of thewater supply device 50 so as to operate according to the receivedinstruction. In this embodiment, the motor of the water supply device 50is controlled so as to take in the water.

The humidity of the space part S of the manhole M is controlled by thesteps S301 to S308.

As described above, the humidity adjustment device 10 according to thepresent embodiment further includes the communication unit 13 forcommunicating with the water supply device 50 installed in the manholeM. The control unit 11 of the humidity adjustment device 10 determinesthe operation of the water supply device 50 so that the humidity ismaintained in the range of the reference humidity value or more and lessthan the critical humidity value, and transmits the determined operationto the water supply device 50 via the communication unit 13.

According to the present embodiment, the humidity in the manhole M canbe controlled more accurately by controlling the operation of the watersupply device 50. By the operation of the water supply device 50, thehumidity in the manhole M can be maintained at the humidity where theprogress of neutralization of concrete is suppressed and dewcondensation does not occur.

As described above, in the humidity adjustment device 10 according tothe present embodiment, the control unit 11 acquires the water amountinformation indicating the water amount in the water supply device 50,calculates the required water amount of the water supply device 50 onthe basis of the space part temperature information, the inner wallsurface temperature information, the humidity information, and theinformation indicating the critical humidity value, determines theoperation of the water supply device 50 on the basis of the result ofcomparing the required water amount with the water amount in the watersupply device 50, and transmits the determined operation to the watersupply device 50 via the communication unit 13.

According to the present embodiment, the required water amount of thewater supply device 50 is calculated more accurately on the basis of thetemperature and humidity of the space part S of the manhole M and thetemperature of the ceiling surface R included in the inner wall surfaceI. The water supply device 50 can control the operation of taking waterinto the water supply container 51 on the basis of the calculatedrequired water amount, so that the inside of the manhole M can be alwaysmaintained at appropriate humidity.

Although the present disclosure has been described based on drawings andexamples, it should be noted that various modifications and correctionscan be easily made by those skilled in the art based on the presentdisclosure. Therefore, it should be noted that such modifications andcorrections fall within the scope of the present disclosure.

Modification Example 1

As a modification example of the present disclosure, the control unit 11of the humidity adjustment device 10 may further include a sealingproperty determination unit 114.

As will be described in detail below, the sealing property determinationunit 114 judges whether or not there is sealing property in the manholeM.

The sealing property determination unit 114 first reads out the humidityinformation stored in the storage unit 12 and the hygroscopic propertyinformation indicating the hygroscopic property of the concreteconstituting the manhole M stored in advance in the storage unit 12. The“hygroscopic property information” includes a humidity drop amountreference value, a humidity change reference tendency, and a durationreference value of humidity drop. Here, the hygroscopic propertyinformation is set according to a humidity control property of theconcrete constituting the manhole M. The humidity control property ofthe concrete refers to the performance of moisture absorption whenconcrete is dried as compared with the surrounding environment andmoisture desorption when the concrete is wet as disclosed in thefollowing Literatures 5 and 6.

Literature 5: Hiroyuki Tanaka, and other, “Difference in void structureand humidity control performance of cement-based solidified material dueto difference in aggregate”, the 67th Annual Conference of the JapanSociety of Civil Engineers, V-448, 2012

Literature 6: Katsuhiko Goto, and other, “Structure and humiditycontrolling performance of zeolite-cement hardened body”, Journal of theCeramic Society of Japan, Vol. 113, No. 1, PP. 736-742, 2005

The “humidity drop amount reference value” is a value indicating areference of the humidity drop amount in the manhole M. The drop amountin humidity in the closed manhole M in a fixed time is measured inadvance, and the drop amount is used as the humidity drop amountreference value. It has been found that the rate of moisture absorptionby the concrete is low, and the humidity drop amount in the manhole Mconstituted of the concrete is relatively small. Therefore, the humiditydrop amount in the closed manhole M is measured in advance and themeasured value can be used as a reference value.

The “humidity change reference tendency” indicates a tendency of achange with time in humidity in the manhole M. In the closed manhole M,the humidity change tendency in a certain time is measured in advance,and the measured tendency is used as the humidity change referencetendency. The size and shape of the manhole are determined by thestandard, and in the manhole of the same size and shape, the humiditychange tendency due to the moisture absorption function of the concreteis similar. Therefore, the humidity change tendency in the manholehaving the same size and shape is grasped beforehand, and this tendencycan be used as a reference for determining the other manhole.

The “duration reference value” is a value indicating a duration of thehumidity drop in the manhole M. In the closed manhole M, the time forcontinuing the humidity drop is measured in advance, and the measuredtime is used as the duration reference value. The humidity drop due tomoisture absorption of the concrete stops after the lapse of a fixedtime as long as the inside of the manhole is maintained in a highhumidity environment, but the humidity drop does not stop or restartseven if it stops once in the manhole having a low sealing. Therefore,the duration of the humidity drop is measured in advance and themeasured duration can be used as a reference value.

The sealing property determination unit 114 determines whether or notthere is the sealing property of the manhole M by comparing humidityincluded in the humidity information with the humidity change referencetendency, the humidity drop amount reference value, or the durationreference value. For example, the sealing property determination unit114 determines that there is the sealing property of the manhole M whenthe humidity change tendency matches the humidity change referencetendency. For example, the sealing property determination unit 114determines that there is the sealing property of the manhole M when thehumidity drop amount is less than the humidity drop amount referencevalue. For example, the sealing property determination unit 114determines that there is the sealing property of the manhole M when theduration of the humidity drop is less than the duration reference value.The sealing property determination unit 114 may determine the sealingproperty by using any one of the humidity change reference tendency, thehumidity drop amount reference value, and the duration reference value,or may determine by using a plurality of reference values.

The control unit 11 notifies a user of the result determined by thesealing property determination unit 114 via the output unit 15. Thus,the user can grasp the sealing property of the manhole M. The controlunit 11 may transmit the determined result to a terminal device of theuser who inspects the manhole M via the communication unit 13.

In the present modification, the operation determination unit 112 maydetermine the operation performed by the humidifier 20 or the watersupply device 50 in accordance with the result determined by the sealingproperty determination unit 114. For example, when the sealing propertydetermination unit 114 determines that there is no sealing property ofthe manhole M, the operation determination unit 112 may determine theoperation of the humidifier 20 so that the humidifier 20 performs alarge amount of humidification. For example, when the sealing propertydetermination unit 114 determines that there is no sealing property ofthe manhole M, the operation determination unit 112 may determine theoperation of the water supply device 50 so that the water supply device50 takes in the water. The operation instruction determined by theoperation determination unit 112 is transmitted to the humidifier 20 orthe water supply device 50 via the communication unit 13, and thehumidifier 20 or the water supply device 50 may operate according to theinstruction.

As described above, in the humidity adjustment device 10 according tothe present modification, the control unit 11 determines whether or notthere is the sealing property of the manhole M on the basis of thehumidity information.

According to this modification, the presence or absence of the sealingproperty of the manhole M can be easily grasped. By grasping the sealingproperty, humidity in the manhole M can be properly maintained, and itcan be found at an early stage that the iron cover 230 of the manhole Mis detached, or that a damaged part exists in the manhole M, etc. Thus,the occurrence of an accident in the manhole M can be prevented.

As described above, the control unit 11 of the humidity adjustmentdevice 10 according to the present modification determines the sealingproperty based on the humidity control property of the concreteconstituting the manhole M.

According to this modification, when the humidity in the manhole M isdropped, it is easy to determine whether the drop is caused by moistureabsorption of the concrete constituting the manhole M or due to nosealing property. Thus, the presence or absence of the sealing propertyof the manhole M can be grasped more accurately.

Modification Example 2

As a modification example of the present disclosure, the humidityadjustment device 10 may further include a dehumidification device. Inthis modification, the humidity adjustment device 10 controls theoperation of the dehumidifier in addition to the operation of thehumidifier 20 or the water supply device 50.

According to this modification, the humidity in the manhole M can beadjusted more quickly and accurately by using the dehumidifying functionof the dehumidifier. For example, when the humidity outside the manholeM is high, or when rainwater enters the manhole M, the humidity of thespace part S is quickly reduced by the dehumidifier, and the humiditycan be prevented from reaching the critical humidity value.

Modification Example 3

As a modification example of the present disclosure, the control unit 11of the humidity adjustment device 10 may estimate the temperature of theceiling surface R of the manhole M from the temperature included in thespace part temperature information instead of acquiring the temperaturefrom the inner wall surface thermometer 40. For example, the controlunit 11 may analyze the temperature included in the space parttemperature information and the depth of the manhole M previously storedin the storage unit 12 as parameters to estimate the temperature of theceiling surface R. The details of the method for measuring thetemperature of the ceiling surface R by analyzing the temperature of thespace part S of the manhole M and the depth of the manhole M asparameters are disclosed in, for example, the following Literature 7,and therefore the description thereof will be omitted.

Literature 7: Kazuaki Watanabe, and four others, “Estimationhydrothermal condition concrete in manhole for information network byintegrated heat transfer analysis of soil and structure”, Journal ofJapan Society of civil engineers, Ser.E2 (Materials and ConcreteStructures), Vol. 76, No. 2, PP. 65-77, 2020

According to this modification, since the control unit 11 can acquirethe temperature of the ceiling surface R without installing the innerwall surface thermometer 40 in the manhole M, the humidity in themanhole M can be controlled with a simpler configuration.

Modification Example 4

As a modification example of the present disclosure, the control unit 11of the humidity adjustment device 10 may acquire the temperature of thespace part S of the manhole M from the optical fiber using a sensingtechnique instead of acquiring the temperature of the space part S fromthe space part thermo-hygrometer 30. The optical fiber is included in acommunication cable installed in the manhole M. The details of thesensing technique of the optical fiber are disclosed in, for example,the following Literature 8, and therefore the description thereof isomitted.

Literature 8: Tokuo Yamaguchi, and other, “Distributed optical fibertemperature sensing”, OKI technical review, No. 203, Vol. 84, No. 2,2017

According to this modification, the control unit 11 can acquire thetemperature of the space part S without using the space partthermo-hygrometer 30 in the manhole M, so that the humidity in themanhole M can be controlled with a simpler configuration.

Modification Example 5

As a modification example of the present disclosure, the humidityadjustment device 10 may include a moisture absorption/desorptionmaterial having moisture absorption/desorption properties instead of thehumidifier 20 and the water supply device 50, or in addition to thehumidifier 20 and the water supply device 50. The moistureabsorption/desorption material may be installed along the whole innerwall surface I of the manhole M, for example.

According to this modification, the humidity in the manhole M can becontrolled by a simpler configuration.

REFERENCE SIGNS LIST

-   -   1,2 System    -   10 Humidity adjustment device    -   11 Control unit    -   12 Storage unit    -   13 Communication unit    -   14 Input unit    -   15 Output unit    -   111 Critical humidity value calculation unit    -   112 Operation determination unit    -   113 Required water amount calculation unit    -   114 Sealing property determination unit    -   20 Humidifier    -   30 Space part thermo-hygrometer    -   40 Inner wall surface thermometer    -   50 Water supply device    -   51 Water supply container    -   52 Cover    -   53 Water supply tank    -   54 Water supply passage    -   55 Water level sensor    -   210 Neck part    -   220 Frame part    -   230 Iron cover    -   221 Ceiling part    -   222 Floor part    -   223 Side wall part

1. A humidity adjustment device, the device comprising a processorconfigured to execute a method comprising acquiring humidity informationindicating humidity of a space part of a manhole; and adjusting, basedon the humidity information, the humidity of the space part of themanhole.
 2. The humidity adjustment device according to claim 1, theprocessor further configured to execute a method comprising: acquiringspace part temperature information and inner wall surface temperatureinformation, wherein the space part temperature information includes atemperature of the space part of the manhole, and wherein the inner wallsurface temperature information includes a temperature of an inner wallsurface of the manhole; calculating a critical humidity value at whichdew condensation does not occur in the manhole based on one or more of:the space part temperature information, the inner wall surfacetemperature information, and the humidity information; and adjusting thehumidity of the space part of the manhole based on a result of comparingthe critical humidity value with the humidity.
 3. The humidityadjustment device according to claim 2, the processor further configuredto execute a method comprising: determining an operation for maintainingthe humidity within a range equal to or greater than a referencehumidity value and less than the critical humidity value; andtransmitting data for humidifying the inside of the manhole.
 4. Thehumidity adjustment device according to claim 2, the processor furthercomprises a method comprising: determining an operation for supplyingwater in the manhole to maintain the humidity within a range equal to orgreater than a reference humidity value and less than a criticalhumidity value; and transmitting data for maintaining the humidityaccording to supplying water in the manhole.
 5. The humidity adjustmentdevice according to claim 4, wherein the acquiring the space partinformation further comprises: acquiring acquires water amountinformation indicating a water amount associated with supplying water inthe manhole, calculating a needed water amount based on one or more of:the space part temperature information, the inner wall surfacetemperature information, the humidity information, or the informationindicating the critical humidity value, determining the operation ofsupplying the water based on a result of comparing the needed wateramount with the water amount, and causing transmission of the determinedoperation to supply the water.
 6. The humidity adjustment deviceaccording to claim 1, the processor further configured to execute amethod comprising: determining whether or not there is sealing propertyin the manhole on the basis of the humidity information.
 7. The humidityadjustment device according to claim 6, the processor further configuredto execute a method comprising: determining the sealing property basedon humidity control property of concrete constituting the manhole.
 8. Amethod for adjusting humidity inside a manhole, the method comprising:acquiring humidity information indicating humidity of a space part ofthe manhole; and controlling the humidity of the space part of themanhole on the basis of the humidity information.
 9. The humidityadjustment device according to claim 2, the processor further configuredto execute a method comprising: determining whether or not there issealing property in the manhole on the basis of the humidityinformation.
 10. The humidity adjustment device according to claim 3,the processor further configured to execute a method comprising:determining whether or not there is sealing property in the manhole onthe basis of the humidity information.
 11. The humidity adjustmentdevice according to claim 4, the processor further configured to executea method comprising: determining whether or not there is sealingproperty in the manhole on the basis of the humidity information. 12.The humidity adjustment device according to claim 5, the processorfurther configured to execute a method comprising: determining whetheror not there is sealing property in the manhole on the basis of thehumidity information.
 13. The method according to claim 8, furthercomprising: acquiring space part temperature information and inner wallsurface temperature information, wherein the space part temperatureinformation includes a temperature of the space part of the manhole, andwherein the inner wall surface temperature information includes atemperature of an inner wall surface of the manhole; calculating acritical humidity value at which dew condensation does not occur in themanhole based on one or more of: the space part temperature information,the inner wall surface temperature information, and the humidityinformation; and adjusting the humidity of the space part of the manholebased on a result of comparing the critical humidity value with thehumidity.
 14. The method according to claim 13, further comprising:determining an operation for maintaining the humidity within a rangeequal to or greater than a reference humidity value and less than thecritical humidity value; and transmitting data for humidifying theinside of the manhole.
 15. The method according to claim 13, furthercomprising: determining an operation for supplying water in the manholeto maintain the humidity within a range equal to or greater than areference humidity value and less than a critical humidity value; andtransmitting data for maintaining the humidity according to supplyingwater in the manhole.
 16. The method according to claim 15, wherein theacquiring the space part information further comprises: acquiringacquires water amount information indicating a water amount associatedwith supplying water in the manhole, calculating a needed water amountbased on one or more of: the space part temperature information, theinner wall surface temperature information, the humidity information, orthe information indicating the critical humidity value, determining theoperation of supplying the water based on a result of comparing theneeded water amount with the water amount, and causing transmission ofthe determined operation to supply the water.
 17. The method accordingto claim 8, further comprising: determining whether or not there issealing property in the manhole on the basis of the humidityinformation.
 18. A system for adjusting humidity, the system comprisinga processor configured to execute a method comprising: acquiringhumidity information indicating humidity of a space part of the manhole;and controlling the humidity of the space part of the manhole on thebasis of the humidity information.
 19. The system according to claim 18,the processor further comprising a method comprising: acquiring spacepart temperature information and inner wall surface temperatureinformation, wherein the space part temperature information includes atemperature of the space part of the manhole, and wherein the inner wallsurface temperature information includes a temperature of an inner wallsurface of the manhole; calculating a critical humidity value at whichdew condensation does not occur in the manhole based on one or more of:the space part temperature information, the inner wall surfacetemperature information, and the humidity information; and adjusting thehumidity of the space part of the manhole based on a result of comparingthe critical humidity value with the humidity.
 20. The system accordingto claim 19, the processor further comprising a method comprising:determining an operation for maintaining the humidity within a rangeequal to or greater than a reference humidity value and less than thecritical humidity value; and transmitting data for humidifying theinside of the manhole.